/* 全局样式 */
body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

/* 导航栏样式 */
header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    text-align: center;
}

nav ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: flex-end;
}

nav ul li {
    margin: 0 10px;
}

nav ul li a {
    text-decoration: none;
    color: #333;
}

/* 顶部宣传区域样式 */
.hero-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 50px;
}

.hero-content {
    max-width: 50%;
}

.hero-content h1 {
    font-size: 68px;
    margin-bottom: 20px;
}

.hero-content p {
    font-size: 18px;
    margin-bottom: 30px;
}

.btn-primary {
    background-color: #007BFF;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
}

.btn-secondary {
    background-color: transparent;
    color: #007BFF;
    border: 1px solid #007BFF;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
}

.hero-image img {
    max-width: 100%;
    height: auto;
}

/* 统计数据区域样式 */
.stats-section {
    display: flex;
    justify-content: space-around;
    padding: 50px;
    background-color: #f9f9f9;
}

.stats-item {
    text-align: center;
}

.stats-item h2 {
    font-size: 30px;
    margin-bottom: 10px;
}

/* 热门课程区域样式 */
.popular-courses-section {
    padding: 50px;
}

.popular-courses-section h2 {
    font-size: 24px;
    margin-bottom: 20px;
}